1. Field of the Invention
The present invention relates to an image forming device for forming in the air an image of pictures or characters drawn or displayed on a surface, and also relates to a touch-less display switch which utilizes such an image forming device.
2. Description of the Prior Art
Conventionally, static or animated pictures or characters displayed on a picture plane of a display device are adapted to be observed by an observer while he visually recognizes the picture plane itself through a surface structure of the display device.
However, such pictures or characters are those merely displayed on the picture plane, and they lack amusingness.
In addition, various kinds of display switches called xe2x80x9ctouch-panel switchesxe2x80x9d have been proposed. In general, such switches are disposed on an upper surface of a display device and have a common basic construction which includes a contactor or a specific member having a variable impedance covered by a transparent sheet. The contactor is normally made of a transparent electrode.
Here, the term xe2x80x9ctouch-panel switchxe2x80x9d means a multi-function switch (operable as an input/output terminal as well as a switch) which is operable to open and close its contact when an operator touches or pushes a transparent sheet (or a contact) of the switch with his finger(s), or when the finger(s) of the operator is moved away from the transparent sheet after contacting the same.
Since, with the conventional touch-panel switch, the operator has to touch the transparent sheet of the switch after he visually recognizes keys which are displayed on a picture surface of the display device and which are positioned at the back of the transparent sheet, there has been a serious drawback that the transparent sheet tends to be stained in addition to the drawbacks of lack in amusingness of the display device itself.
Further, for the reason of stains, the conventional touch-panel switch is not suitable for use as an input/output terminal for an instrument or an apparatus in which particular consideration should be given to sanitary aspect.
For example, as for an operation switch for a medical instrument, it is often desirable that the switch is turned on and off while the operator does not touch the switch. As is well known, in recent years, nosocomial infection by virus has been a serious problem. Thus, the conventional touch-panel switch is not appropriate to be used where it is not suitable for uses where the operator directly touches a switch (or its keys).
It is, accordingly, an object of the present invention to provide an image forming device which serves to form an image of pictures or characters in a visually specific manner.
It is another object of the present invention to provide a touch-less display switch which permits an operator to operate the switch without touching the switch while the operator visually recognizes an image of keys of the switch which has been formed in a special form.
It is a further object of the present invention to provide a touch-less display switch which does not cause stains on the switch or keys as well as fingers of an operator when the switch is operated.
It is a still further object of the present invention to provide a touch-less display switch which is advantageously used as an input/output terminal of an instrument where particular consideration should be given to sanitary aspect.
According to a first aspect of the present invention, there is provided an image forming device for placement on a surface on which pictures or characters are drawn or displayed, comprising a lens member including a plurality of distributed-index rod-like lens elements disposed in juxtaposed relationship with each other in a matrix-like arrangement and operable to map the pictures or characters as a visual real image on substantially one image plane in the air spaced from said surface.
With the first aspect, for example, static or animated pictures or characters displayed on a picture surface of a display device are mapped by the lens member as a visual real image in the air space from the picture surface. Thus, an observer or an operator can observe the image in the air risen from the actual picture surface, so that the image thus obtained is very unique and provides excellent view.
According to a second aspect of the present invention, there is provided a touch-less display switch for use in combination with a display device, comprising:
a lens member including a plurality of distributed-index rod-like lens elements disposed in juxtaposed relationship with each other in a matrix-like arrangement. and operable to map pictures or characters displayed on a picture surface of the display device as a visual image on substantially one image plane in the air in spaced relationship with the picture surface; and
a sensor having a detection area corresponding to at least a part of the mapped image on said image plane and operable to detect an object entering said detection area in a non-contact manner.
The lens elements may have a predetermined length and having flat upper and lower ends, so that the lens member has flat upper and lower surfaces.
The lens member is positioned above the display device such that the pictures or characters displayed by the display device are mapped on the image plane as a visual real image in the air above the lens member.
When an object such as a finger(s) of an operator enters the detection area of the sensor positioned on or adjacent the image plane of the mapped image, the sensor detects the position of the object or a particular area part (one of area parts of the detection area) to which the position of the object belongs.
The pictures or characters displayed by the display device may include a plural kind of keys, so that the keys are mapped on the image plane in the air by means of the lens member. Thus, the operator can visually recognize the image of the keys floating in the air and can move his finger to touch or select either one of the keys as the visual image. When the finger of the operator enters the particular area part of the detection area of the sensor corresponding to the selected key, the sensor outputs a corresponding output signal.
The output signal from the sensor may be used for converting the pictures or characters currently displayed by the display device into another ones and may be also used for controlling a suitable device or instrument associated with the switch.
The invention will become more apparent from the appended claims and the description as it proceeds in connection with the drawings.